Motor fuels containing inhibitors



Patented Nov. 1935 I I UNITED STATES PATENT OFFICE anew MOTOR FUELS CONTAINING INHIBIT-B8 Herbert G. M. Fischer, Westfldd, and Clifford E.

Gostafson, Elizabeth, H. 1., ami'gnorl to Galoline Antioxidant Company No Drawing. Application 10, 1933,

Serial No. 675,380

comma. (0144-9) The preseht invention relates to improvements til a drop in pressure of 2# below maximum is in low-boiling, non-viscous hydrocarbon oils, such recorded. This period is generally called the inas naphtha and the like, andwill be fully underduction period, at the end of which it will generstood from the following description. ally be found that the gasoline will contain be- Hydrocarbon oils, such as naphtha, which intween 20-30 mg. of gum as measured by the 5 cludes gasoline, and particularly such naphthas preformed gum test. p as are made by decomposition of heavier oils and noted above, cracked naphthas containing the like, often contain gum or gum-forming conrelatively large quantities of gum are objectionstituents which are objectionable in many reable, particularly for motor fuels, cle naphspects. The exact nature of these objectionable thas, light solvents, and the like. It is a so well impurities is at present unknown, but the gum known that on standing the gumcontent ofmany content, or, more properly, gum formation tennaphthas steadily increases; We have discovered dency, is measured by the method Number 530.1 that the addition of mixtures of certain organic in the United States Bureau of Mines, Technical materials to the naphtha, even though in very 5 Report 323-3, entitled Specification for Petrosmall quantities, greatly reduces the gum as inleum Products and Methods of Testing", revised dlcated by the above described tests and also pre- October 21, 1927, page 96. In brief, this method vents an increase of gum for prolonged, if not inconsists in placing 100 cc. of the naphtha to be definite, periods.

tested in a 3%" diameter spun copper dish on We have observed that mixtures of certain dea. steam bath and evapora ofl the volatile rivatives of polycyclic compoimds, such as naphm t ri flier'esult is expressed in milligrams thalene, anthraoene and phenanthrene, are useof gum left in the dish per 100' cc. of the naphml for our purpose. The substitution of certain tha. Another method for determining the tengroupsin the alpha position great y 1116188585 the dency of products of this type to form gum is eifect of the addition agents, for example, we known as the breakdown method, which meashave observed that mixmres of agents such as uresthe resistance of a gasoline to oxidation as alpha naphthol and alpha naphthylamine may follows: A givenquantity of guoline is placed be added to the gasoline with g resultsand at atmospheric temperature into a suitable bomb that volatile metallic compounds, such as mewhich is connected to a pressure gauge of either tallo-organic substances, which are useful for indicating or recording type. After the bomb is their anii-detonating eflfects, may be present in tightly closed, oxygen is allowed to flow into the the na hthas without any adverse action. bomb until apressure of l00#/sq. in.is recorded. The quantity of the addition'agents is very The omen supply is then shut ofl and discon-' small, not being greater in anycase than 5.81. nected. The bomb and its contents are'then per liter of the naphtha and generally between heated in a suitable bath to a temperature .of the te limits of .01 to 1.0 gr..per liter. 100 C. Upon heating, the pressure will rapidly There appears to be an optimum quantity of the rise to a maximum (say 1251?) and remain at agents which will give the best results and it is this point until active oxygen absorption by the a simple matter to makeup solvents of different gasoline takes place, when a more or less rapid andem irically select the most suitable dropin pressure will be noted. concentration. a 40 The resistance to oxidation of. the gasoline is The following table indicates the effect obnumerically expressed in minutes andis taken as tamed. by alphanaphthol and alph the time elapsed from the'application of heat unnaphthylamine to cracked stock (gasoline).

Base stock used: Non-acid treated soda-washed cracked stock Gdmeootmt Total Inhibita' em -dill: W 1hourum 0d amut: from Q 7 I n as as 12550 Burdockd M n rm a 1m +m9tn$3m in us an 205,; +11%!! mp tl i i riem h g g {g i? +.01 p naph ylunine +.1m5% htholondmwyb'al a In I m +mfimtmmdmmy m m m r 'IThe term naphthalene compounds having certain substituted groups, is used in this speci- The explanation for the enhanced sum inhibiting eirect of the mixed antioxidants is believed to be that the combined action of these antioxidants or naphthalene compounds having certain substituted to be limited by any theoryoi the mechanism oi the process nor by any example given merely by way of illustration, but onb by thefollowing claims in which we wish to claim all novelty inherent in the invention.

This application is a continuation in part of our copending application 307,545 flied September 21, 1928.

We claim:

1. The method at inhibiting the formation of gum in cracked 2. As a composition of matter a low boiling hydrocarbon oil prepared by heat treatment at a decomposition temperature and normally tend-' mixture of anti -oxidants comprising alpha substituted aromatic condensed ring hydrocarbons in which adjacent nuclei have two carbon atoms in common, some of said having anaminosubstituentandotheranhydroxysub- 5 stitutent. a

3. The method of inhibitingthe formation of gum in cracked gasoline, which comprises adding to said gasoline a small proportion of a mixture of anti-oxidants comprising a substance having 10 the characteristics of alpha naphthol and a sub- HERBERT a; ransom crummy a. Gum-Arson. s5

clnracteristics of 20 

